style.scss

.ui-autocomplete {
  position: absolute;
  top: 100%;
  left: 0;
  z-index: 1000;
  float: left;
  display: none;
  min-width: 160px;
  padding: 4px 0;
  margin: 2px 0 0 0;
  list-style: none;
  background-color: #ffffff;
  border-color: #ccc;
  border-color: rgba(0, 0, 0, 0.2);
  border-style: solid;
  border-width: 1px;
  border-radius: 5px;
  box-shadow: 0 5px 10px rgba(0, 0, 0, 0.2);
  background-clip: padding-box;

  .ui-menu-item {
    display: block;
    padding: 3px 15px;
    clear: both;
    font-weight: normal;
    line-height: 18px;
    color: #555555;
    white-space: nowrap;
  }

  .ui-state-focus {
    color: #ffffff;
    text-decoration: none;
    background-color: #0088cc;
    border-radius: 0px;
    background-image: none;
  }
}

// move the screen reader help out of sight for regular browsers,
// but it will stil work for screen readers
.ui-helper-hidden-accessible {
  position: absolute;
  left: -9999px;
}

// In Rails, this assumes the loading image is in assets/images
.ui-autocomplete-loading {
  background: white url('ui-anim_basic_16x16.gif') right center no-repeat;
}

Bootstrap friendly UI for Jquery autocomplete. This is a first pass at updating it for autocomplete 1.11.2